Emerging MEMS sensors for ocean physics: Principles, materials, and applications

The use of ocean sensors is crucial for exploration of the ocean and harnessing the potential of its resources. However, conventional ocean sensors are limited by their fabrication techniques, which result in sensors that are large in size, have high-power consumption requirements, and involve complex deployment processes. However, fulfilling observation requirements in the harsh marine environment presents a formidable challenge for these devices. Microelectromechanical system (MEMS) technologies offer a promising solution that will enable development of a new generation of ocean sensors that offer superior performance. This paper focuses on MEMS-based ocean sensors that have been designed to measure both essential physical parameters and fundamental processes within the marine environment, including the ocean's conductivity, temperature, and depth, ocean currents, ocean turbulence, earthquakes, seafloor deformation, and ocean acoustic signals. The fundamental designs of these sensors, including their working principles, structures, properties, and fabrication procedures, are illustrated in the individual sections. The paper also discusses the important challenges that MEMS ocean sensors may encounter, along with their prospects for future development. By highlighting the potential of MEMS-based ocean sensors, this review aims to contribute to the development of more efficient and reliable ocean observation systems.